Pump drive at combustion engines



April 10, 1956 F. K. H, NALlfxNGER PUMP DRIVE AT COMBUSTION ENGINES Filed NOV. 7, 1950 Hamer/r;

United States Patent ,I

PUMPl DRIVE AT coMaUsrroN ENGINES Friedrich K. H. Nallinger, Stuttgart, Germany, assigner to Daimler-Benz Aktiengesellschaft, Stuttgart-Untertnrkheim, Germany Application November 7, 1951i, Serial No. 194,411

Claims priority, application Germany November 10, 1949 22 Claims. (Ci. 10S-23) 'I'he invention refers to a pump drive for combustion engines, particularly a fuel pump drive for motor vehicle engines.

One object of the invention is to improve the reliability in service of electrically driven fuel pumps.

In accordance with this object, one characteristic feature of the invention is that the piston or membrane of the pump is driven by a shaft, which in turn is driven by an electromotor, wherein the drive by the electromotor can be the only driving means or anadditional drive of the shaft. Hereby the advantage is achieved that the drive by the electromotor takes place through structural elements, which are reliable, for example through a camshaft or a crankshaft.

It is a further object of the invention to achieve a care ful treatment of the electrical equipment, for example a current consumption, which is as economic as possible. In accordance with this object, it is a further characteristic feature of the invention that provision is made for driving the pump from both an electric drive and a mechanical drive by the combustion engine. The switching from one to the other drive can hereby be effected optionally or automatically, suitably in such a manner that the switching on or activating of the electrical drive is effected optionally for example simultaneously with the switching on of the ignition, and the switching oif or inactivating of the electric drive on the contrary is eiected automatically.

The arrangement of an optionally active electrical drive in addition to a mechanical drive has particularly the advantage that the electrical drive alone may be used, when possibility of driving the pump by the combustion engine is not satisfactory, for example either because the latter is not running or because it is idling at insuflcient speed. A further advantage is that the pump can also be put to service, if the electrical drive fails. The current consumption can be kept low, in that for example the electromotor is or can be inactivated by switching oft' the supply of current upon completion of the starting procedure. The electrornotor can hereby run permanently; it is, however, suitably automatically brought to a complete standstill, if occasion arises, with time delay after switching off the starter or in another suitable dependence upon the condition of the combustion engine.

According to a further characteristic of the invention the arrangement can be made in such a manner that upon switching on of the electrical drive the mechanical drive is uncoupled from the pump, for example by means of an overrunning clutch or similar device. inversely suitable provision is made for an overrunning clutch, which permits the mechanical drive to replace the electric drive in its turn, for example when the combustion engine reaches a higher number of revolutions upon completion of the starting. Provision can also be made for both freewheels atthe same time.

If occasion arises, the alternate coupling of the pump with the electrical drive on one hand and the drive by the combustion engine on the other hand can also be effected 2,741,186 Patented Apr. 1o, 195s by a change coupling, which can be operated optionally or automatically.

In the drawing some examples of construction of the v the electrical and mechanical drives and with switching oit of the electromotor in dependence upon the temperature of the engine and Figure 4 shows a modilication of Figure 3 with switching oi of the electromotor in dependence upon the pressure of the conveyor iiuid.

The piston 2, which is guided in the pump cylinder l, is pressed against the cam 4 of a driving shaft 5 by means of a spring 3. The fuel is admitted through a suction valve 6 and is discharge through a pressure valve 7 to the combustion engine, for example to the fuel injection pump of same or to another part of the engine, where it is required.

The camshaft is in the example of construction in accordance with Figure 1 coupled directly with an electromotor 8. The circuit 10 for the current, which is supplied by a source of any type (for example a vehicle battery), can be interrupted by means of a switch 9. The closing or opening of the switch 9 can be executed optionally, for example by the driver or automatically or semi-automatically, in that for example the closing of the switch and thereby the starting of the electromotor takes place simultaneously with the switching on of the ignition current or of the starter, upon switching off of the starter, however, the electromotor 8 continues working.

In the example of construction in accordance with Figure 2 a change coupling 11 of any type, for example a dog clutch, is keyed on the camshaft 5 for axial displacement thereon and rotation therewith, which couples the shaft 5 either with the toothed wheel 12, which is driven by the combustion engine, or with the electromotor 8. The change coupling 11 is operated by a lever 13, which is adjusted by a piston 14 through rod 14'. The piston 14 is loaded on its right side by a spring 15, which seeks to displace it to the left and to couple thereby the shaft 5 with the electromotor 8. The left side 16 of the piston is connected a conduit 17 with the control space 18 of a slide valve 19, which is under the eect of al spring 2i). From the cylinder of the slide valve 19 a conduit 21 leads to the outside, for example back into the sump 22 of a control fluid. A second conduit 23 is in con` nection with the pressure conduit 24, for example the lubrication oil conduit of the engine, vinto which the liquid is conveyed under pressure from the sump 22 by means of the pump 25, which is driven by the engine. The side 26 of the slide valve 19, which is opposite to the spring 2i), is in connection with the pressure conduit 24 of the pump by a conduit 27 through a throttle boring 28, which can be adjustable, if occasion arises.

The switch 9, which is arranged in the energizing circuit of the electromotor, is furthermore under the effect A of a spring 29, which urges it in the closing direction. On the rod 30 there 'is a nose 31, in the range of movement of whicha latch 32 is arranged, which can for example be pressed forward by a spring and can be withdrawn from the range of movement of the nose Si by means of an electromagnetic relay 33'. The latter can for example be connected to the starter circuit, in such' a manner that they are both supplied with current by means of the switch 34 or also independently from the starter optionally by the driver.

Furthermore a stop 35 rod 30 in the' range of the stop 36 on such a manner that in the fully drawn lever 13 and thus the switch can.

nal position (i..e,.upon.couplinggof.5,and 11..with.each.r i

other). therodfis; oudhe contrary, shifted to.- the.. right by the stop 36 and thereby the switch 9 is opened,.where.

by. the.latch.32,.is.lifted.by the nosel. andlocks-.the .latter iruthe right iinallposition.

'Ehe manner; of operationoffthearrangementrin accordanceewith'FigpreZislthe following: Y

Ifl therengiue; and.. therebyV also; the. pumptZS (..for eX- ample. the lubricatingl oil; pump Qi thef. engine.) stands. still,4 the conduit 24. and. therewith. also.. the.. conduit, 27 are without pressure. Consequentlydhespring 20 presses this slide 'valve` 1-9- downward, sofv that thepi'ston space 16 isdischargedthroughsl'l,.1.8, 2.1..

. The spring 15 presses the piston-f 1.410.the.left,wherel1y the electtomotor 8 is:v coupled; with thedriving shaft, 5 of the fuel4 pump. Since;Y however, the.. switch. 9. is, locked by. the latch` 32the motor-f8 stillfrcceives no current.

lfA the engine is. to. be started, the. driver closes the.

switch. 3.4, whichcan simultaneously.Y also switch. on the.y

' yignition current. ror can. bring the starter, into action.

Thereby the latch 32 is lifted and the rod 3D is released.

4`r is in this case a snap or operating lever 39, which is drawn alternately into its one or other tinalpositionY byv a spring 40 and hereby closes or interrupts the circuit.

A further lever 41, which is operated by the driver op- K n tionally (or for example together with the starter), can act upon the lever 39 in such a manner that by rotation of the. lever 41. inan anticlockwise directionfor., example upon starting of the engine, the switch 39* is cl'osed with snapactionand alsothen remainsfin, this positiom-when the. lever 41 is returned: to its originali positiom (.'for eX- stop 42 acts upon the lever 39 which stop isconnpcted with a thermostat relayy 43. The latter is arranged in a The spring, pressesgthelatten tothe'left andthe switch 9 closes, whereby the electromotor 8f is.. brought: into.

actionandfdrives the pump piston 2. Withthe starting of, the. engine'. also the oil in the. conduit. 2.4. 1s placed, under pressurerand-starts now, to load the slide valve 19.

from the-pressure space,v 2li` through the throttle boringl28.4

and thecnndnit. 27 andto displace itin upwarddirection againstv theetectof the.- spring'Zt. The, preliminary tenf sion of the. spring 2,0 can hereby be selected. in such a. manner that, thei adjustment begins'only ata certain tiuid pressure in the conduit. 24kmV displace.V the. slidel valve. 1.9. When the slide valve 19. hasv carried out a certain stroke upward,tl:teV discharge conduitY 21 is cut off, from the controlspace 18 and the pressure conduit23.. isl brought. into: connection; with. it.. In this moment thepressure fluid can ow from; the conduit 23 through` the control space 18, to the conduit: 17; andl thereby tothe: pstonside 16 and displace the pistonto the right against. the eiecto thespring 15. This hasv as, its.. consequencev that. the. shaft 5 is nncoupled from the electromotott Sand isinsteadoi this coupled with the, combustion1 engine through the Y toothed. wheel, 12. Simultaneously theswitchV opened by pressing hack thel stop. and the. electromotor, is. stopped.4 The; rod. 3.0 locks itself` on byengaging the nosewith theY latch.32 asfsoonqas. the switch, 34 has;be env openedf-for example after completion, of` the;- starting.

A'It'. theengine stall.s,the. pressure inthe conduit 24 falls hack. to zero again, whereby. the;v slide. valve- 19. (ii occa? sion arises,v withV time delay). displaces.. itself; again. downward. 'lhe piston,- space 16,` willA again. be. without pres sure andv the; piston 14 is. displacedtov the left., The. changecoupling. 1 1. switchesover again andy couples the. shaft.- Swith theelectromotor 8...

'In the4 example. of. construction., in accordance with Figurethe camshaftS, iscOupIedwith the toothedwheel vmotor 8 is uncoupled from the shaft, 5,. if. the latter-is driven bythe-toothed wheel 1.2 in. hefsamdireetinllf O ff rotation. with/a higher; number. of; revolutions' than the electromotor 8.

in the energizing` circuit l0' of the electromotor there;

conduit; 44,y for. example the lubricating oil.' conduitiof the combustion engine. lt occasion aris,es,'the transmission of the shifting power of the thermostat relay to the stop 42 and the operating lever 39 can also be executed through; a servomoton rlhe.. manner of operation. of with Figure 3 is the following:

In-` coldconditionof the. enginethe stop.v42..is,ol1.t$ide of the range of mov-.ement of the, operating; lever 3.9,',sothat-itdoesnot hamper the-shifting over of same by the lever.. 4.1. Withthe closing of thel operating2 lever 39. the clectromotor 8. receives current and. drives the.l shaft 5,- andthereby the piston` 2 of` thefuelI pump through, the. couplings, As. soon as the engine` and therewith the` lubricating. oil have becomej warm, thethermostat relayz 43 expands itself, if,the. lever` 41A was nQtIemmQd UNIE: illustrated position after completed starting; PlQCdDr-er and displaces the operating lever to the left'by;mean;I Qfg; thestop 42,. so that theV supply of current for. the electromotor 8 is interrupted. Y

Thestoppingotthe. clectrcmotor has-asi consequence that the pump. piston is now drivenl by the combustion. engine; through the; toothedwheel; 1:2.. and,the.overrun,njngrv c1utch.37.whi1c.theovcrrunningclutch ir1t.c.rr.1.1pts;auto.` matically the driving connection between the .electrornotpr Sandthe; shaftS.

In the case. of. the examplecf construction in. accorde ance with Figure 4e the. thermostat relay' 43 is. rcplaccdr by. aj piston. 4.5, whichis on. one;side-under; the etectfofga'. springi-and onthe other side undenthe.p retltllreof.;the.` Huid... which. ows in at 47. Again. thelubricatinsfoik oi; the engine caribe utilizedl as. pressure uid. Assocntaszthe engine reaches acertainnumber.r ci:revolutions.;an.fithrrclntr the. uidisplaccd. undcrfprcssurc, the piston 45. disglaccs; itseltto,l the lett. andi thereby'- switchcs ott; the. electromotors; Y

'Iheinventiou is. not rcstrictcdto-theillustratcdeaample ci. construction,l but can; be varied. at; diaclzetion; within thebounds of. the individual; ideasgcf; the invention.

Whatl claim, is:v

1. A-.drivefor a. pump-in` acombustinnenginecnmprif ing a. pumpv member, electrical.- means; tot: drivin said Pump membcn mechanical means. for driving;said4 hump. member. from the engine, cooperativeA coupling Ineens: connected to. said: pump member and ta said; elec drive means and-mechanical drive meanesaid. cooperative coupling means being operative to couple saidpumpgmemy. ber. to.. one. ot said electrical. and mechanical. drive. means, alternatively.. and. automaticfmeans..respcnsiveto timonel?.g ating, condition of the engine, rendering Said. clcctnicd drive means inoperative Ywhen the engine achieves aprecieter-,n linedl operating condition and then preventingvthe, ref newal--of operation of said' electrical drive means' during thecontinued maintenance of said predetermined" operl ating condition.

2. A. drive,- forapump in a combustion` engine according to. claim- 1;, furthercomprising` any electrical circuit'ftarA elllgzingfsaidelectrical drive means and having al trol switch therein, and means for closing-said.' control" the device. ine accordance switchtduringstartingfof theengine'.

rst driving member connected to said mechanical drive means, a second driving member connected to said electri' engine and connected to said control member to move the latter to a first position, in which said driven member is engaged with said second driving member, until the engine attains said predetermined operating condition and to move said control member to a second position, in which said driven member engages said first driving member, after the engine attains said predetermined operating condition, an electrical circuit for energizing said electrical f drive means and having a control switch therein, switch actuating means movable to open and close said control switch, and means on said control member engageable with said switch actuating means and operative, during movement of said control member to said second position thereof, to displace said switch actuating means in the direction opening said control switch and to prevent movement of said switch actuating means in the direction closing said control switch so long as said control member remains in said second position thereof.

5. A drive for a pump in a combustion engine according to claim 4; further comprising means urging said switch actuating means in the direction closing said control switch, and locking means operative to hold said switch actuating means against movement in the direction closing said control switch.

6. A drive for a pump in a combustion engine according to claim 5; further comprising an electrical starter circuit for the engine, and electrical means interposed in said starter circuit to render said locking means inoperative upon energization of said starter circuit.

7. A drive for a pump in a combustion engine to claim 1; wherein said automatic means includes a control member connected to said coupling means and movable between a rst position, in which said pump member is coupled to said electrical drive means, and a second position, in which said pump member is coupled to said mechanical drive means, and actuating means sensing the operating condition of the engine and connected to said control member to move the latter to said lirst position until the engine attains said predetermined operating condition and to move said control member to said second position when the engine attains said predetermined operating condition.

`8. A drive for a pump in a combustion engine according to claim 7; wherein said automatic means further includes an electrical circuit for energizing said electrical drive means and having a control switch therein, switch actuating means movable in opposite directions to open and close said control switch, and means on said control member engageable with said switch actuating means and operative, during movement of said control member to said second position thereof, to displace said switch actuating means in the direction opening said control switch and to prevent movement of said switch actuating means in the direction closing said control switch so long as said control member remains in said second position thereof.

9. A drive for a pump in a combustion engine according to claim 8, further comprising means urging said switch actuating means in the direction closing said control switch, and locking means operative to hold said switch actuating means against movement in the direction closing said control switch.

l0. A drive for a pump in a combustion engine accord- 6 ing to claim 9; further comprising an Velectrical starter circuit for the engine, and electrical means interposed in said starter circuit to render said locking means inoperative upon energization of said starter circuit.

1l. A drive for a pump in a combustion engine in accordance with claim l; further comprising a driven shaft actuating said pump member, and wherein said coupling means includes a first overrunning clutch between said mechanical drive means and said driven shaft and a second overrunning clutch between said electrical drive means and said driven shaft, said rst and second overrunning clutches interrupting the coupling between said driven shaft and said mechanical and electrical drive,

means, respectively, when said electrical drive means is operative and inoperative, respectively.

l2. A drive for a pump in a combustion engine in accordance with claim 1l; further comprising an electrical circuit for energizing said electrical drive means and having a control switch therein, a control member connected to said control switch to move the latter between open and closed positions; and wherein said automatic means includes a blocking member movable between a first position, in which it engages said control member and prevents movement of the latter in the direction for closing said control switch, and a second position remote from said control member to-permit movement of the latter in the direction for closing said control switch, and actuating means connected to said blocking member and ensing the operating condition of the engine to dispose said blocking member in said second position thereof until the engine achieves said predetermined operating condition and to dispose said blocking member in said rst position thereof so long as said predetermined operating condition of the engine is maintained.

13. A drive for a pump in a combustion engine in accordance with claim l2; wherein said actuating means includes a thermostatic member responding to the engine temperature.

14. A drive for a pump in a combustion engine in accordance with claim l2; wherein said automatic means further includes an operating lever engageable with said control member to move the latter in the direction closing said switch.

15. A drive for a pump in a combustion engine in accordance with claim 1; wherein said coupling means includes overrunning clutches coupling said pump member to said electrical drive means and to said mechanical drive means, alternatively, when said electrical drive means is operative and inoperative, respectively; and wherein said automatic means includes means for operating said electrical drive means, and means responsive to f the engine temperature to render said electrical drive means inoperative when the engine temperature reaches a predetermined level.

16. A drive for a pump in a combustion engine in accordance with claim l; wherein said coupling means includes overrunning clutches coupling said pump member to said electrical drive means and to said mechanical drive means, alternatively, when said electrical drive means is operative and inoperative, respectively; and wherein said automatic means includes means for operating said electrical drive means, means driven by the engine to establish a lluid pressure characteristic of the engine speed, and means responsive to the fluid pressure to render said electrical drive means inoperative when the tiuid pressure reaches a predetermined level.

17. A drive for a pump in a combustion engine in accordance with claim l; further comprising a control member movable between a lirst position and a second position, said control member being connected to said coupling means to condition the latter for coupling said pump member to said electrical drive means, when said control member is in said first position thereof, and to condition said coupling means for coupling said pump member to saidv mechanical drive means, when said con` trol? is: im said second' positiom thereof; and! wherein said automatic means2 includest actuatingr meansconnected 'to said control? member` and yiel'dabl)f urging; the latter to said'ttrstrpositiomtl'iereof, arndlmeansm sense ingr the operating@condtionfof thefeng-ine and' operative to move said actuating= means= inr thedirection A displacing saidicontrolf member 'to saidl second?position:thereeffwlfien the engine achieves A saidi predetermined operating 4 condi-'- tion.

1'8. A4A driveI for pumpin-^a combustionA engine' inA ac'- Y cordance with c1aim=1'7; whereinsaidisensing means includes de1ay means for retardingL the movement of' said actuating-'meansimsaid direction after'the engine achieves said Y' predeterminedoperating condition;

19. A drive for a pumpinarcombustionhengine;ae cording to claim 17;'--wliereinsaidautomatiemeans further includes af idpmnpdrivenl by the engineso thatthev pressure develope by said'4 iuidf pump isz characteristic; ofi4 theu engine speed; andisaid: sensing means responds= to thepressuredeveiopedfby saidfuidfpump.

202 A driveffor-wpumpinacombustionengineaccord;l

cylinder, a Vpiston''working -irrsaidcylinderA and 'lconnected'i to,..said control-v member; anda= spring-'- in=rsaid cylinder movementfothe latter; and-ivalve-meansfinterposed in atl a'- predetermined pressure bysaid'VA uid pump toi-moves* to a1 secondV position in* which it t communicates-15e latter' Y witli said cylindersthatthepressuref of'thezfluidl actssiii said`=cylinden to move-*said piston,againstsaidfspring.`

212 A .drive fori a1l pump' in a= combustion* enginetae cortli'ngV to'cl`aim-20`; Whereinsaidfvalve' means"-includesL a valve member slidable in a valve housing, resilient* meansi'urgingA sailvalve member to* saidiirst position 4 thereof, saidV valve member Havingl a'` plungerh thereoni Withina portion-of; saidhousing, and av control conduit* leadingffrom' said-uid' pumpito' said'` portion of th'eeli'ous# ing sothatfthe'pressnreeiiuidlaets1inl thevlatter against ssiili plunger trii overcomes the-v effect of f said resilient meansfV whensaid'predetermined "pressure ofi the :Huidisfa'chi'e'vf'e'rlit 22;y A: drive-forr a pump' in acorn-bustionfengineeaecori?w ing4 to claim` 21; further comprising"I a restriction in said* controLconduit tordelayfthe-movement foffthe'valvemeans" to.saidsecond' position of th'eflatte' afterftle pressurefluid"` reaches@said'-` predetermined pressuresv ReferencesfCite'inthe:tile ofithisipatentr I UNITED STA'IESLPATBNTS" 1,167,509 MacDonalds Jan. 1,1, 19,169 1,244,667 v Wellington.A Oct., 3,0, f 1.9.1.7@l 1,907,110. HobartY f May 21.1933 2,959,830,l Warner .Nov. 3;-,1936A Ba1ton........... r.......MMayy 13,-...LMT/L ..A 

